The proliferation of portable and laptop computers has greatly expanded the need for consistent, reliable power sources. A laptop computer is limited by the power available from the internal batteries. When the batteries become discharged, a source of power is needed to recharge them. Typically, a laptop computer includes a power adapter for connecting the laptop computer to a power utility outlet for recharging the batteries and powering the computer. However, there are no standards for power adapters or laptop computers. Different brands of laptop computers require different power levels and/or different voltages. Thus, power adapters are not interchangeable and can only be used with a specific brand or model computer. If a power adapter is lost or malfunctions, it cannot be easily replaced.
Furthermore, travelers who regularly use laptop computers sometimes have access to wall outlet power, but often do not have access to a power utility outlet, such as when they are on an airplane or in a car. Such locations, however, typically have power outlets by may have different types and/or voltages of power sources. Airlines have begun installing power connectors for providing DC power for passenger equipment. Automobiles have “cigarette lighters” or similarly designed power jacks which provide 12 volt DC power from the automobile battery. Some trucks use two series-connected 12 volt DC batteries to power the truck and thus have cigarette lighter outlets that provide 24 volts DC. Regular laptop power adapters cannot utilize these power sources. Additionally, international travelers encounter utility power connectors which differ from those in the United States. For example, utility power in Europe is typically 230 volts compared to 120 volts in the United States. The power connections are also different. While computer manufacturers produce power adapters for a variety of power sources including automobiles, airplanes and international sources, these power adapters often have to be purchased separately. A traveler often has to carry a variety of power adapters to be utilized in different situations.